[Server] Add UseMiddlewares function to server package. (#11)

server/middleware.go

@@ -0,0 +1,21 @@
+package server
+
+import (
+	"sync"
+
+	"github.com/mwm-io/gapi/handler"
+	"github.com/mwm-io/gapi/middleware"
+)
+
+var middlewareMU sync.Mutex
+
+// UseMiddlewares appends a given list of handler.Middleware to middlewares chain.
+//
+// Middleware can be used to intercept or otherwise modify requests and/or responses, and
+// are executed in list order.
+func UseMiddlewares(middlewares ...handler.Middleware) {
+	middlewareMU.Lock()
+	defer middlewareMU.Unlock()
+
+	middleware.Defaults = append(middleware.Defaults, middlewares...)
+}